Designs for a device called a microwave thruster, which could power spacecraft without the need for propellant, have been proposed since 2006. While the engine follows the principles of relativity theory in converting electrical energy into force to produce thrust, it has been dismissed as impossible in practice since it defies the law of conservation of momentum. But a team from NASA has just successfully trialled their own version of the engine, which changes everything.

Several years ago British scientist Roger Shawyer presented his EmDrive microwave thruster engine to the scientific community. It used microwaves bounced off reflectors in a sealed container to produce small amounts of force and thereby achieve propulsion via propellant-free thrust. Its possibilities for long-distance spaceflight were extraordinary, but while it was groundbreaking there was one catch: it defied the law of conservation of momentum and was therefore deemed theoretically flawed. In 2012, scientists in China successfully repeated Shawyer’s development, but still most of the scientific community didn’t pay much attention to the results.

Now a team at NASA has tested the Cannae Drive developed by U.S. scientist Guido Fetta. It too is a microwave thruster and it was presented as a successful test at the recent 50th Joint Propulsion Conference in Cleveland, Ohio. The drive produced 30 to 50 micronewtons of thrust, which was decidedly less than the Chinese team’s reported 720 millinewtons or Shawyer’s 16 to 30 millinewtons. The NASA team’s report stated: “Test results indicate that the RF resonant cavity thruster design, which is unique as an electric propulsion device, is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma.” I believe that translates as, “We are not entirely sure why, but it works.”

However, if like NASA we choose to focus on the results and not the method for the moment, what could be the implications of a microwave thruster-powered spacecraft? The device is so interesting because it does away with the need for lugging along a fuel supply that is about equivalent in weight to the craft it is propelling. Using solar energy to generate the power to create the microwaves in the first place becomes an option too. This would mean the engine could continue indefinitely, at least until mechanical failure brought it to a halt, though it would also limit the craft’s range to proximity to a source. For now, however, NASA’s development doesn’t even provide enough thrust to propel a peanut through space at a mission-acceptable speed, so there is still a way to go to scale up to a mission to Mars.

@Kenny you misquoted the author, she said could not propel a peanut 'at a mission-acceptable speed.' So instead of schooling her on her lack of scientific understanding, all you've managed to do here is show that you can't read at a 3rd grade level.
Furthermore, the construction 'a journalist/they're writing about' is wrong, as the subject is singular.
Listen, you'll be much happier when you can balance your scientific genius with an elementary school ability to use the language, so quick, get to work!

blows me away how insignificant people think this is and that science can now bypass combustion for momentum in space even in a testing and proofing stage is phenomenal! beside the secret space program is already in interstellar and dimensional space its still nothing in the scheme of things but maybe its something they are willing to let us have cause they dont know how to implement it...but in some garage somewhere some dude has developed a way to capture microwave energy using a microwave resonance reflector...maybe

IF you "NASA confirms" you mean that "NASA does not confirm" then you are correct. It was an unreviewed conference paper. By applying more controls than previous papers had they found less thrust. However, they didn't even test it in a vacuum. If the working unit produced a little extra heat than the control the air currents on the device would have produced that much thrust.

This is the worst article I've seen so far on this subject.
"NASA’s development doesn’t even provide enough thrust to propel a peanut through space"
^^ This is an example of a journalist that doesn't even attempt to understand the material they're writing about.
Any amount of force (no matter how insignificant) can always propel any amount of mass (no matter how large).
Sure, it might take a lot longer, but this engine could thrust a peanut with ease. The engine, as it already stands, could be used to propel a typical space probe with no modifications.
There's no resistance in space!